Spend time and money on your child's education

Research on  education funding:

We next turn to student outcomes, focusing on analogous measures of the relationship between district mean test scores and the log mean household income in the school district. Using our event study framework, we find that the “progressivity” of test scores grows significantly – that scores rise in low-income districts relative to high-income districts – in the years following a finance reform, indicating that the extra school resources received by the former districts are used productively. The (local) average effect of an extra $1,000 in per-pupil annual spending is to raise student test scores ten years later by 0.18 standard deviations. 

.18 standard deviations is not too robust in the context, especially since pensions are underfunded. But in the context of parents or parent/teachers spending their own time and money on their own kids the results is likely much better.